Do not set parent_id within koji metadata for custom base image
Do not set parent_id within koji metadata for custom base image

Related to CLOUDBLD-10237

Signed-off-by: Chenxiong Qi <7a7314576eb0408cef5766c0268b5ff02ad3cfb6@redhat.com>

fr34k8/atomic-reactor,fr34k8/atomic-reactor